Revisiting O1-antitrypsin therapy in cystic fibrosis: can it still offer promise?

T he contribution of the neutrophil-derived serine protease neutrophil elastase (NE) to lung disease in cystic fibrosis (CF) is unquestioned and yet, despite promising preliminary studies in the last 20 yrs to investigate an effective therapy to negate the damaging effect of NE [1], this treatment has failed to take off for patients with CF. This is largely due to the scarcity of clinical trial data relating to this therapy. However, two recent publications [2, 3] signal a renewed interest in the application of treatment with inhaled O1antitrypsin (AAT) as a panacea for the proteolytic damage occurring in CF lung disease.